nbc news, atlanta. >> well, 13,000 people did something that most people in the cold freezing winter won't. that i willingly jumped into the icy chesapeake bay to raise money. some did it every hour for an entire day. rob roblin introduces us to the motivation behind the superstars. >> the super plungers started plunging friday morning. time after time they went into the cold water. one time every 24 hours. >> go! >> whoo! >> this is the 10th anniversary of the sup -- super plunge. it all started with three people. one was special olympics athlete jimmy myrick. >> this started 0 years ago with you and tom and greg shipley. did you ever think it would be this big and this great? >> actually, it's great to be this big, but i want more people to come. >> jimmy couldn't plunge this year, he has been fighting leukemia, so others plunged for him. >> to actually see him back here, that was motivational for us. it was a very cold night but knowing he was there late last night and early this morning. i heard he was up at 5:00 a.m. ready to come back over here? incredible. that's the support h